Current Research

My research is on systematics of basidiomycete fungi in North America and neighboring areas of the Neotropics. This includes identification of fungal specimens from surveys and inventories, research to improve basidiomycete classification, and studies to increase knowledge of fungal diversity and distribution. I am using molecular, DNA-based techniques to augment the identification of species and to determine the phylogenetic relationships among populations in the Caribbean, Central America and North America.

I am currently studying systematics of boletes from North America, and I am especially interested in the effects of environmental and climate changes on changes in diversity and distribution of boletes and other beneficial symbionts of tree roots that are known as 'ectomycorrhizal fungi'. This is a natural extension from my doctoral research on boletes from Belize and the Dominican Republic. In addition, I am currently working on systematics of the genus Wolfiporia, a group of wood decay fungi in the family Fomitopsidaceae, and continuing a study of the genus Agaricus, a group of decay fungi that includes edible species such as Crimini and Portabello mushrooms. The Agaricus study is on collections from Puerto Rico, the Virgin Islands and the Dominican Republic.

Research Interests

Continuing systematics studies of boletes in North America. Complete phylogenetic analyses among Caribbean, Central and North American populations.

Continuing studying the effect of environmental and climate changes in the diversity of mycorrhizal fungi.

Continuing systematics studies of Wolfiporia and other wood decay fungi.

Study the systematics of the genus Macrocybe (family Tricholomataceae).

Why This Research is Important

Some mushrooms are important in the forest ecosystems as nutrient recyclers while others form beneficial symbioses with trees roots, known as mycorrhizae. Most trees rely partly or entirely for nutrient and water uptake and protection from pathogens, toxic metals in soils and drought on mycorrhizal fungi, which are beneficial root symbionts. Wood decay fungi are especially important as decomposers because they reduce debris that can fuel forest fires and because they release nutrients that are bound up in dead wood thereby making them available for tree growth. Some native fungi are tree pathogens, which while having negative effects on individual trees, often have beneficial effects in creating habitat for wildlife and contributing to landscape heterogeneity that can limit spread of wildfires. Introduced forest pathogens, however, can produce devastating effects in forest ecosystems and landscapes. Many species of fungi are important as food for invertebrates and mammals, including humans.

Fungal systematics studies provide critical information for delimiting species, understanding changes in fungal and tree distributions and diversity in response to climate and other environmental changes, and the ecological roles of these organisms in forest ecosystems. It is important to have reference collections and inventories of fungi so we can compare and understand the variation in their morphological and genetic characters, their geographical distribution and to determine how environmental (e.g., acid rain and nitrogen inputs from air pollution) and climatic changes may affect their diversity and distribution. Fungi from neighboring tropical areas are likely to invade North America as climates change, so it is critical to know what fungi are near our borders, how to distinguish them from native species, and what effects they have on forests.

National Research Highlights

The culture collection and herbarium maintained by the Center of Forest Mycology Research (CFMR) in Madison, Wisconsin is one of the largest fungal 'libraries' in the world. The collection specializes in fungi associated with wood and contains both living fungi and dried reference specimens, which are used by researchers world-wide in studying forest pathology, disturbance biology, fungal genetics, distribution of invasive species, and impact of climate change on forest ecosystems. The CFMR's web-enabled database, accessible at http://www.fpl.fs.fed.us/research/centers/mycology/culture-collection.shtml, has recently been enlarged and updated.